Device optical biosensors capable of detecting molecules have become useful for the biological sciences to characterize molecules such as proteins, DNA, viruses, toxins, and the like. Some molecular characterization methods employ a discrete bio-reagent, an optical fiber and spectrum system, and a dispensing system. Using optical resonances in a dielectric microparticle, also known as a whispering gallery mode (WGM), as the physical transducing mechanism is a common approach for characterizing molecules.